Design Help Wanted: Flashlight to Jumpstart Your Car.

Flashlight Modding and DIY Parts
1

Hi all,

12/19/17 EDIT: Here is a PDF on the light. I thought it looks pretty good so far but I am recommending they have it edited by a native English speaker.
https://docs.google.com/document/d/1UUQzf11I4g29zeZ2wNhz_vZ3pqYsMuEco4EzwzN2ZiE/edit?usp=sharing

Looking for as much feedback as we can get. Especially if you have CAD experience.

This is not my project, I am assisting a fellow Missourian (Gary). He is from my area, a flashlight enthusiast but not a forum member. He has asked me to post here to get feedback as he’s not posted on a forum since Apple in the 1980s :slight_smile:

Basic Outline:
The primary function of this light is to be a high powered flashlight that has the capability of a power bank. A set of jumper cables is included. The pack is rated to be 15,000ma @ 3.7. If I understand correctly it’s 3x 5,000ma lipo cells with a 40C discharge rating in a 3S config, so that rating may need to be more clearly defined. An early prototype has been sent to him, that we tested. My truck is a 94 F150 with a 300 straight 6. With no battery connected only the flashlight it was able to crank my engine from cold and start it.

The LED is an XHP70. Early tests showed only 1600 lumen output, but at my suggestion they are planning a direct thermal path copper mcpcb with higher drive current on max, and a tempreture sensor will also be implemented.

EDIT: User interface
Define:
Moon mode: 54 lumens (Current 700mA)
Medium mode: 1800 lumens (Current 2.0A)
Burst mode: 4000 lumens (Current 5.3A)
Normal work mode: 1650 lumens (Current 1.65A)

1 Open the flashlight: Long push the switch button,
Default : Low mode, it’s around 54 lumens, That called “Moon mode”
If you push the button shortly again, It enters medium mode, It’s 1800 lumens (Current around 2A);
If you push the button shortly once, It enters burst mode(High lumens), It’s 4000 lumens (Current around 5.3A);
At this moment, It lasts 90 seconds or Temperature reaches 80 degree, The lumens begins to reduce to 1800 lumens (2A), Then it still lasts 90 seconds, The lumens begins to reduce to 1650 lumens (1.65A), It’s normal bright and work current, Until the power goes down.

2 Blink mode:
When the flashlight turns on status, Double click the button, The system remembers the light rank (Memories which lumens value), Then flashlight enters blinking mode:
A From Moon or Normal work mode to blinking: Slow blinking
B From Medium mode to blinking: fast blinking
C From Burst mode to blinking: SOS blinking
At any blinking mode, Just only shortly click button, The flashlight comes back to flashlight turns on status, And enter the memories lumens value.

3 Temperature protection:
When the flashlight work temperature reaches 80 degree, the system will reduce lumens to 1800, then continues to reduce to 1650 lumens, Then keep this bright turn on, Until battery is no power.

*Primary feedback we are looking for at this time is

  1. Cosmetic. What do you think of the look of it? How could it be improved?
  2. What do you think of the user interface?
  3. Overall functionality? Do you see this as a useful product? How could it be made better?*
















2

what is “the user interface”?

one thing strikes me about these things, they are very easy to blow up or destroy

the flat ones sort of puff up one of the cells and that goes high impedance, sort of protecting the rest from high currents.

the cables too are usually very small and also subject to melting, at least the insulation…

i don;t see a high-current output

what will the cost be?

what will the light pattern be?

it also needs to have usb output for charging phones and whatnot.

wle

3

NarsilM user interface with FET + one 12V Linear 350mA regulator similar to AMC7135, the ones available have problems with low PWM values, so probably need to change the Moonlight value

Klarus uses silicone covers with 2 o-ring shapes so it fits very tight

That big silicone boot, needs definitely something to stiff it up, like a thin PCB material attached to it, but usually glue something to silicone is a pain, maybe produce it from reinforced silicone?

but on the other hand you have a tail cap, so the silicone thing on the back is kind of counter productive

.

I would stick with just the tail cap, the thread not to the edge, give a few mm clearance for o-ring sealing
And make the threads square cut and with about 1mm pitch, too small triangular threads wear out too fast and can be hard to screw on with larger diameters

Also some Lanyard attachment like Tail cap with holes is always useful

and have a small cord to hold it to the body so it cant get lost, like “shit it fell in my trucks engine”

Same for the head, give the thread a clearance for o-ring and sink a groove for it on the body

.

Do you want to keep the body made from a pipe, then you have to machine a press fit shelf, like Klarus has in their G35 when you push the XHP70 to 12V 3-4A,

XHP70 DTP star is good, but on 12V get one that has the thermal pad insulated like SinkPad II

Those Sinkpads are OK, MTN, Fasttech and LEDDNA sells em

This LED star will not work if both the star and battery are not insulated from the body, so as if you use the tube for conducting current

4

I think the battery should be a LIPO, maybe a 3S or 4S 4000mah 15C or more like these these can deliver 15 amps easy to turn on the car, I have started cars using a 3S 5000 lipo

5

Just now I added a PDF link to the OP which has a bunch of great info.

UI is
Define:
Moon mode: 54 lumens (Current 700mA)
Medium mode: 1800 lumens (Current 2.0A)
Burst mode: 4000 lumens (Current 5.3A)
Normal work mode: 1650 lumens (Current 1.65A)

1 Open the flashlight: Long push the switch button,
Default : Low mode, it’s around 54 lumens, That called “Moon mode”
If you push the button shortly again, It enters medium mode, It’s 1800 lumens (Current around 2A);
If you push the button shortly once, It enters burst mode(High lumens), It’s 4000 lumens (Current around 5.3A);
At this moment, It lasts 90 seconds or Temperature reaches 80 degree, The lumens begins to reduce to 1800 lumens (2A), Then it still lasts 90 seconds, The lumens begins to reduce to 1650 lumens (1.65A), It’s normal bright and work current, Until the power goes down.

2 Blink mode:
When the flashlight turns on status, Double click the button, The system remembers the light rank (Memories which lumens value), Then flashlight enters blinking mode:
A From Moon or Normal work mode to blinking: Slow blinking
B From Medium mode to blinking: fast blinking
C From Burst mode to blinking: SOS blinking
At any blinking mode, Just only shortly click button, The flashlight comes back to flashlight turns on status, And enter the memories lumens value.

3 Temperature protection:
When the flashlight work temperature reaches 80 degree, the system will reduce lumens to 1800, then continues to reduce to 1650 lumens, Then keep this bright turn on, Until battery is no power.

2.Gary was very insistent on metal clamps for this, we do want to make this a tool and not a gimmick. If you have a suggestion for a material or thickness etc for the shrink surrounding the cables let me know.

3.The battery pack I found out is a 3S lipo made of 5000ma cells with a 40C discharge rating.

4.We are working on getting some beam profile shots posted to youtube, but basically its a “throwy” light with a medium hot spot and bright spill.

5.I don’t have pricing info exactly yet. It wont be a “budget light” Target is “under $200” which could end up being $189 or much closer to $100ish.

6.There is a USB and some other goodies shown in the PDF I just linked.

6

1. I have my concerns about the switch boot too. I see like 2 or 3 different looking designs they have and am not very happy with any of them yet.

2. The option for a lanyard is a good idea, I will mention that also.

3. I cant remember if they had square threads on the prototype or not, but I think that is a good idea as well.

7

I found out the pack is 3s lipo 5000ma 40C max discharge. They are rating it as 15000ma @ 3.7V. Perhaps this is misleading since the only 3.7V discharge is out the USB port???

8

I looked at li-po jump-starters a few years ago, I found that some (no idea how many) Are susceptible to being reverse-charged by the alternator once the engine has started. Things may have improved since 2014/2015 though.

9

That’s a very interesting idea.
How many 21700-30T would it take to jump-start a car? I have a feeling that if that way is feasible, it would be better than proprietary pack.

10

Nice idea!

I don’t think regular lithiums will work. Crank amp is around 500Amps @ 12V for a medium sized car. It will get way too bulky and heavy.

Maybe add an orange diffuser cap, to place it on the road with a beacon mode to alert traffic of a brokedown vehicle ahead.

And why not use a XHP70.2 LED?

Maybe you can add a tyre compressor as an accessory.

11

Not wanting to be a downer but is this a problem to a solution most folks don’t have?

Who wants to carry a car jumper battery around with them?

Better a phone battery charger so the misses can call for help.

Burly guys if they need a carry a spare battery might just do so or throw one of the endless stream of $50 flat jump battery thingys in the trunk.

love the innovation I’m just concerned that the target market is way smaller then hoped for.

At the end of the day the battery requirements specifications for driving a flashlight and jumping a car are still too far apart for low cost dual purpose power packs.

Racing motorcycles get jump standard to avoid the weight, performance motorcycles use AGM to minimize the weight.
Some day hybrid Supercapacitors and Li-on cells will be cost effective but not today. Sure they can be done but why?
If you need more grunt or reserve the most cost effective start solution is a go 2P SLA.

Sure there are handy flat jumper pack thingys but from what I understand they don’t reliably work well (probably design issues not technology limitations) But who aside form on the side of the road uses them as a flashlight?

Better car batteries for cars and nice flashlights for the task at hand. And if you know if a good Flat Lipo pack jumper thingy great but clearly the market for that product wants cheap (else why all the crap) (Im sure there are goo ones out there but I would not know how to identify them from all the crap).

12

I want one in my car.
Not fully charged, so it won’t “just work when I need it”, but batteries won’t die for years.
If I need it, I can bring it home and charge the cells.
If I’m not home, I can charge it from any USB outlet. Or any car with 12V outlet with charging adapter taken from my car.
So it’s a bit like jumpstart cables which need time instead of another car.
Sometimes what you have is another car. Sometimes it’s time. Sometimes you can get a car around after some time, but charging time is close, so it’s not worth bothering others.
And aside from being a jump-starter, who doesn’t need a 4klum emergency flashlight stored in their car?

13

usually the flat jump starter thingies have a (marginal) led flashlight built in, as well as phone charging jacks.

it just seems to me, to be strong enough to start a car, the thing will have to weigh 4-5 lbs like the flat jump starter thingies do.

wle

14

you should use 90C high discharge LIPO battery, just in case

15

That is a good point which I will look into. If the cells can handle the charge rate at which alternators deliver current, and the pack has sufficient cut off I think that would be ok, possibly even useful. Otherwise steps will need to be taken to ensure this is not possible.

16

This brings up another point. My truck battery is a 650 CCA. If the pack in this light is 5000ma at 11.1v and has a 40C discharge rating that is only 200 amp. Assuming the peak is 80c for 10 seconds 400 amps gets us in the safe zone (since its not likely the 11.1V will crank engine nearly as hard), but I’m wondering still if going bigger might render a better long term and more reliable result.

17

and how do you handle the cables [which should be big and have a fuse or other protection]?

wle

18

Solved by a diode.
All of those jump starters have a bunch of diodes in series, the current can only go one way.

19

I actually think this is an excellent idea. I try to make sure I have a working flashlight and jumper cables in every car I own. I’ve been wanting one of those lithium car jumper things, but haven’t got a good excuse to get one. This flashlight would be a great tool to carry in the glove box of the car, ready when needed. :wink:

That “strike bezel” though. :person_facepalming:

20

While I like the idea of being able to jump start a vehicle with a flashlight, the light seems to be much bigger than any lights I like to use as a flashlight. My commonly used lights are single 18650 cell types, or smaller. No one product suits us all.